654 lines
17 KiB
C
654 lines
17 KiB
C
#include <pico/stdlib.h>
|
|
#include <pico/stdio_usb.h>
|
|
#include <pico/multicore.h>
|
|
#include <pico/util/queue.h>
|
|
|
|
#include <hardware/clocks.h>
|
|
#include <hardware/dma.h>
|
|
#include <hardware/gpio.h>
|
|
#include <hardware/pll.h>
|
|
#include <hardware/vreg.h>
|
|
#include <hardware/sync.h>
|
|
#include <hardware/pio.h>
|
|
#include <hardware/pwm.h>
|
|
#include <hardware/interp.h>
|
|
|
|
#include <hardware/regs/clocks.h>
|
|
#include <hardware/structs/bus_ctrl.h>
|
|
|
|
#include <math.h>
|
|
#include <stdio.h>
|
|
#include <limits.h>
|
|
#include <stdlib.h>
|
|
|
|
#define VREG_VOLTAGE VREG_VOLTAGE_1_20
|
|
#define CLK_SYS_HZ (306 * MHZ)
|
|
|
|
#define RX_PIN 10
|
|
#define FB_PIN 11
|
|
#define PSU_PIN 23
|
|
|
|
#define PIO pio0
|
|
#define SM_RX 0
|
|
#define SM_BIAS 1
|
|
#define SM_COS 2
|
|
#define SM_SIN 3
|
|
|
|
#define IQ_SAMPLES 32
|
|
#define IQ_BLOCK_LEN (2 * IQ_SAMPLES)
|
|
#define IQ_QUEUE_LEN 8
|
|
|
|
#define XOR_ADDR 0x1000
|
|
#define LO_BITS_DEPTH 15
|
|
#define LO_WORDS (1 << (LO_BITS_DEPTH - 2))
|
|
#define LO_COS_ACCUMULATOR (&PIO->sm[SM_COS].pinctrl)
|
|
#define LO_SIN_ACCUMULATOR (&PIO->sm[SM_SIN].pinctrl)
|
|
#define SIN_PHASE (0u)
|
|
#define COS_PHASE (3u << 30)
|
|
|
|
static uint32_t lo_cos[LO_WORDS] __attribute__((__aligned__(1 << LO_BITS_DEPTH)));
|
|
static uint32_t lo_sin[LO_WORDS] __attribute__((__aligned__(1 << LO_BITS_DEPTH)));
|
|
|
|
#define DECIMATE 4
|
|
|
|
#define INIT_SAMPLE_RATE 100000
|
|
#define INIT_FREQ 94600000
|
|
|
|
#define BASE_GAIN (1 << 15)
|
|
#define ATTN_BITS 8
|
|
|
|
static int sample_rate = INIT_SAMPLE_RATE;
|
|
static int gain = BASE_GAIN / (CLK_SYS_HZ / INIT_SAMPLE_RATE / 2);
|
|
static int frequency = INIT_FREQ;
|
|
|
|
static queue_t iq_queue;
|
|
static uint8_t iq_queue_buffer[IQ_QUEUE_LEN][IQ_BLOCK_LEN];
|
|
static size_t iq_queue_pos = 0;
|
|
|
|
static uint32_t xorshift_seed;
|
|
|
|
static inline __unused uint32_t xorshift(void)
|
|
{
|
|
uint32_t x = xorshift_seed;
|
|
x ^= x << 13;
|
|
x ^= x >> 17;
|
|
x ^= x << 5;
|
|
xorshift_seed = x;
|
|
return x;
|
|
}
|
|
|
|
static void dma_channel_clear_chain_to(int ch)
|
|
{
|
|
uint32_t ctrl = dma_hw->ch[ch].al1_ctrl;
|
|
ctrl &= ~DMA_CH0_CTRL_TRIG_CHAIN_TO_BITS;
|
|
ctrl |= ch << DMA_CH0_CTRL_TRIG_CHAIN_TO_LSB;
|
|
dma_hw->ch[ch].al1_ctrl = ctrl;
|
|
}
|
|
|
|
/* rx -> cp -> cos -> sin -> pio_cos -> pio_sin -> rx ... */
|
|
static int dma_ch_rx = -1;
|
|
static int dma_ch_cp = -1;
|
|
static int dma_ch_cos = -1;
|
|
static int dma_ch_sin = -1;
|
|
static int dma_ch_pio_cos = -1;
|
|
static int dma_ch_pio_sin = -1;
|
|
|
|
static int dma_ch_samp_cos = -1;
|
|
static int dma_ch_samp_sin = -1;
|
|
|
|
static int dma_t_samp = -1;
|
|
|
|
static int origin_rx = -1;
|
|
static int origin_bias = -1;
|
|
static int origin_adder = 0;
|
|
|
|
static void init_rx()
|
|
{
|
|
gpio_disable_pulls(RX_PIN);
|
|
pio_gpio_init(PIO, RX_PIN);
|
|
|
|
const uint16_t insn[] = {
|
|
pio_encode_in(pio_pins, 1) | pio_encode_delay(0),
|
|
};
|
|
|
|
pio_program_t prog = {
|
|
.instructions = insn,
|
|
.length = sizeof(insn) / sizeof(*insn),
|
|
.origin = origin_rx,
|
|
};
|
|
|
|
if (pio_can_add_program(PIO, &prog))
|
|
origin_rx = pio_add_program(PIO, &prog);
|
|
|
|
pio_sm_config pc = pio_get_default_sm_config();
|
|
sm_config_set_in_pins(&pc, RX_PIN);
|
|
sm_config_set_wrap(&pc, origin_rx, origin_rx + prog.length - 1);
|
|
sm_config_set_clkdiv_int_frac(&pc, 1, 0);
|
|
sm_config_set_fifo_join(&pc, PIO_FIFO_JOIN_RX);
|
|
sm_config_set_in_shift(&pc, false, true, 32);
|
|
pio_sm_init(PIO, SM_RX, origin_rx, &pc);
|
|
|
|
pio_sm_set_consecutive_pindirs(PIO, SM_RX, RX_PIN, 1, GPIO_IN);
|
|
}
|
|
|
|
static void init_bias()
|
|
{
|
|
gpio_disable_pulls(RX_PIN);
|
|
gpio_disable_pulls(FB_PIN);
|
|
|
|
pio_gpio_init(PIO, FB_PIN);
|
|
|
|
gpio_set_input_hysteresis_enabled(RX_PIN, false);
|
|
gpio_set_drive_strength(FB_PIN, GPIO_DRIVE_STRENGTH_2MA);
|
|
gpio_set_slew_rate(FB_PIN, GPIO_SLEW_RATE_SLOW);
|
|
|
|
PIO->input_sync_bypass = 1u << RX_PIN;
|
|
|
|
const uint16_t insn[] = {
|
|
pio_encode_mov(pio_isr, pio_null),
|
|
pio_encode_in(pio_y, 4),
|
|
pio_encode_in(pio_pins, 1) | pio_encode_delay(15),
|
|
pio_encode_in(pio_pins, 1) | pio_encode_delay(15),
|
|
|
|
pio_encode_mov(pio_y, pio_isr),
|
|
pio_encode_mov(pio_x, pio_isr),
|
|
|
|
pio_encode_jmp_x_dec(6),
|
|
pio_encode_mov_not(pio_pins, pio_pins) | pio_encode_sideset(1, 1),
|
|
};
|
|
|
|
pio_program_t prog = {
|
|
.instructions = insn,
|
|
.length = sizeof(insn) / sizeof(*insn),
|
|
.origin = origin_bias,
|
|
};
|
|
|
|
if (pio_can_add_program(PIO, &prog))
|
|
origin_bias = pio_add_program(PIO, &prog);
|
|
|
|
pio_sm_config pc = pio_get_default_sm_config();
|
|
sm_config_set_in_shift(&pc, false, false, 32);
|
|
sm_config_set_sideset(&pc, 1, false, true);
|
|
sm_config_set_sideset_pins(&pc, FB_PIN);
|
|
sm_config_set_in_pins(&pc, RX_PIN);
|
|
sm_config_set_out_pins(&pc, FB_PIN, 1);
|
|
sm_config_set_set_pins(&pc, RX_PIN, 1);
|
|
|
|
sm_config_set_wrap(&pc, origin_bias, origin_bias + prog.length - 1);
|
|
|
|
sm_config_set_clkdiv_int_frac(&pc, 1, 0);
|
|
pio_sm_init(PIO, SM_BIAS, origin_bias, &pc);
|
|
|
|
pio_sm_exec_wait_blocking(PIO, SM_BIAS, pio_encode_set(pio_y, 31));
|
|
pio_sm_set_consecutive_pindirs(PIO, SM_BIAS, FB_PIN, 1, GPIO_OUT);
|
|
}
|
|
|
|
static const uint32_t samp_insn = 16;
|
|
|
|
static void init_adder()
|
|
{
|
|
const uint16_t insn[] = {
|
|
/* y has weight of 2, x has weight of 1 */
|
|
pio_encode_out(pio_pc, 4), // 0000 +0
|
|
pio_encode_jmp_x_dec(0), // 0001 +1
|
|
pio_encode_jmp_x_dec(0), // 0010 +1
|
|
pio_encode_jmp_y_dec(0), // 0011 +2
|
|
pio_encode_jmp_x_dec(0), // 0100 +1
|
|
pio_encode_jmp_y_dec(0), // 0101 +2
|
|
pio_encode_jmp_y_dec(0), // 0110 +2
|
|
pio_encode_jmp_y_dec(1), // 0111 +2 +1
|
|
pio_encode_jmp_x_dec(0), // 1000 +1
|
|
pio_encode_jmp_y_dec(0), // 1001 +2
|
|
pio_encode_jmp_y_dec(0), // 1010 +2
|
|
pio_encode_jmp_y_dec(1), // 1011 +2 +1
|
|
pio_encode_jmp_y_dec(0), // 1100 +2
|
|
pio_encode_jmp_y_dec(1), // 1101 +2 +1
|
|
pio_encode_jmp_y_dec(1), // 1110 +2 +1
|
|
pio_encode_jmp_y_dec(3), // 1111 +2 +2
|
|
|
|
/*
|
|
* Should wrap here.
|
|
* Jump to this portion must be inserted from the outside.
|
|
*/
|
|
pio_encode_in(pio_y, 32),
|
|
pio_encode_in(pio_x, 32),
|
|
pio_encode_out(pio_pc, 4),
|
|
};
|
|
|
|
pio_program_t prog = {
|
|
.instructions = insn,
|
|
.length = sizeof(insn) / sizeof(*insn),
|
|
.origin = origin_adder,
|
|
};
|
|
|
|
if (pio_can_add_program(PIO, &prog))
|
|
origin_adder = pio_add_program(PIO, &prog);
|
|
|
|
pio_sm_config pc = pio_get_default_sm_config();
|
|
sm_config_set_wrap(&pc, origin_adder, origin_adder + 13);
|
|
sm_config_set_clkdiv_int_frac(&pc, 1, 0);
|
|
sm_config_set_in_shift(&pc, false, true, 32);
|
|
sm_config_set_out_shift(&pc, false, true, 32);
|
|
|
|
pio_sm_init(PIO, SM_COS, origin_adder, &pc);
|
|
pio_sm_init(PIO, SM_SIN, origin_adder, &pc);
|
|
}
|
|
|
|
#define STEP_BASE ((UINT_MAX + 1.0) / CLK_SYS_HZ)
|
|
|
|
static void lo_generate_phase(uint32_t *buf, size_t len, uint32_t step, uint32_t phase)
|
|
{
|
|
for (size_t i = 0; i < len; i++) {
|
|
uint32_t bits = 0;
|
|
|
|
for (int j = 0; j < 32; j++) {
|
|
bits |= phase >> 31;
|
|
bits <<= 1;
|
|
phase += step;
|
|
}
|
|
|
|
buf[i] = bits;
|
|
}
|
|
}
|
|
|
|
static void rx_lo_init(double req_freq, bool align)
|
|
{
|
|
const double step_hz = (double)CLK_SYS_HZ / ((8 << LO_BITS_DEPTH) / 2.0);
|
|
double freq = req_freq;
|
|
|
|
if (align)
|
|
freq = round(freq / step_hz) * step_hz;
|
|
|
|
uint32_t step = STEP_BASE * freq;
|
|
|
|
lo_generate_phase(lo_cos, LO_WORDS, step, COS_PHASE);
|
|
lo_generate_phase(lo_sin, LO_WORDS, step, SIN_PHASE);
|
|
}
|
|
|
|
static void rf_rx_start()
|
|
{
|
|
dma_ch_rx = dma_claim_unused_channel(true);
|
|
dma_ch_cp = dma_claim_unused_channel(true);
|
|
dma_ch_cos = dma_claim_unused_channel(true);
|
|
dma_ch_sin = dma_claim_unused_channel(true);
|
|
dma_ch_pio_cos = dma_claim_unused_channel(true);
|
|
dma_ch_pio_sin = dma_claim_unused_channel(true);
|
|
|
|
dma_ch_samp_cos = dma_claim_unused_channel(true);
|
|
dma_ch_samp_sin = dma_claim_unused_channel(true);
|
|
|
|
dma_channel_config dma_conf;
|
|
|
|
/* Read received word into accumulator I. */
|
|
dma_conf = dma_channel_get_default_config(dma_ch_rx);
|
|
channel_config_set_transfer_data_size(&dma_conf, DMA_SIZE_32);
|
|
channel_config_set_read_increment(&dma_conf, false);
|
|
channel_config_set_write_increment(&dma_conf, false);
|
|
channel_config_set_dreq(&dma_conf, pio_get_dreq(PIO, SM_RX, false));
|
|
channel_config_set_chain_to(&dma_conf, dma_ch_cp);
|
|
dma_channel_configure(dma_ch_rx, &dma_conf, LO_COS_ACCUMULATOR, &PIO->rxf[SM_RX], 1, false);
|
|
|
|
/* Copy accumulator I to accumulator Q. */
|
|
dma_conf = dma_channel_get_default_config(dma_ch_cp);
|
|
channel_config_set_transfer_data_size(&dma_conf, DMA_SIZE_32);
|
|
channel_config_set_read_increment(&dma_conf, false);
|
|
channel_config_set_write_increment(&dma_conf, false);
|
|
channel_config_set_chain_to(&dma_conf, dma_ch_cos);
|
|
dma_channel_configure(dma_ch_cp, &dma_conf, LO_SIN_ACCUMULATOR, LO_COS_ACCUMULATOR, 1,
|
|
false);
|
|
|
|
/* Read lo_cos into accumulator I with XOR. */
|
|
dma_conf = dma_channel_get_default_config(dma_ch_cos);
|
|
channel_config_set_transfer_data_size(&dma_conf, DMA_SIZE_32);
|
|
channel_config_set_read_increment(&dma_conf, true);
|
|
channel_config_set_write_increment(&dma_conf, false);
|
|
channel_config_set_ring(&dma_conf, false, LO_BITS_DEPTH);
|
|
channel_config_set_chain_to(&dma_conf, dma_ch_sin);
|
|
dma_channel_configure(dma_ch_cos, &dma_conf, LO_COS_ACCUMULATOR + XOR_ADDR / 4, lo_cos, 1,
|
|
false);
|
|
|
|
/* Read lo_sin into accumulator Q with XOR. */
|
|
dma_conf = dma_channel_get_default_config(dma_ch_sin);
|
|
channel_config_set_transfer_data_size(&dma_conf, DMA_SIZE_32);
|
|
channel_config_set_read_increment(&dma_conf, true);
|
|
channel_config_set_write_increment(&dma_conf, false);
|
|
channel_config_set_ring(&dma_conf, false, LO_BITS_DEPTH);
|
|
channel_config_set_chain_to(&dma_conf, dma_ch_pio_cos);
|
|
dma_channel_configure(dma_ch_sin, &dma_conf, LO_SIN_ACCUMULATOR + XOR_ADDR / 4, lo_sin, 1,
|
|
false);
|
|
|
|
/* Copy mixed I accumulator to PIO adder I. */
|
|
dma_conf = dma_channel_get_default_config(dma_ch_pio_cos);
|
|
channel_config_set_transfer_data_size(&dma_conf, DMA_SIZE_32);
|
|
channel_config_set_read_increment(&dma_conf, false);
|
|
channel_config_set_write_increment(&dma_conf, false);
|
|
channel_config_set_dreq(&dma_conf, pio_get_dreq(PIO, SM_COS, true));
|
|
channel_config_set_chain_to(&dma_conf, dma_ch_pio_sin);
|
|
dma_channel_configure(dma_ch_pio_cos, &dma_conf, &PIO->txf[SM_COS], LO_COS_ACCUMULATOR, 1,
|
|
false);
|
|
|
|
/* Copy mixed Q accumulator to PIO adder Q. */
|
|
dma_conf = dma_channel_get_default_config(dma_ch_pio_sin);
|
|
channel_config_set_transfer_data_size(&dma_conf, DMA_SIZE_32);
|
|
channel_config_set_read_increment(&dma_conf, false);
|
|
channel_config_set_write_increment(&dma_conf, false);
|
|
channel_config_set_dreq(&dma_conf, pio_get_dreq(PIO, SM_SIN, true));
|
|
channel_config_set_chain_to(&dma_conf, dma_ch_rx);
|
|
dma_channel_configure(dma_ch_pio_sin, &dma_conf, &PIO->txf[SM_SIN], LO_SIN_ACCUMULATOR, 1,
|
|
false);
|
|
|
|
/* Trigger I accumulator values push. */
|
|
dma_conf = dma_channel_get_default_config(dma_ch_samp_cos);
|
|
channel_config_set_transfer_data_size(&dma_conf, DMA_SIZE_32);
|
|
channel_config_set_read_increment(&dma_conf, false);
|
|
channel_config_set_write_increment(&dma_conf, false);
|
|
channel_config_set_dreq(&dma_conf, dma_get_timer_dreq(dma_t_samp));
|
|
channel_config_set_high_priority(&dma_conf, true);
|
|
channel_config_set_chain_to(&dma_conf, dma_ch_samp_sin);
|
|
dma_channel_configure(dma_ch_samp_cos, &dma_conf, &PIO->sm[SM_COS].instr, &samp_insn, 1,
|
|
false);
|
|
|
|
/* Trigger Q accumulator values push. */
|
|
dma_conf = dma_channel_get_default_config(dma_ch_samp_sin);
|
|
channel_config_set_transfer_data_size(&dma_conf, DMA_SIZE_32);
|
|
channel_config_set_read_increment(&dma_conf, false);
|
|
channel_config_set_write_increment(&dma_conf, false);
|
|
channel_config_set_high_priority(&dma_conf, true);
|
|
channel_config_set_chain_to(&dma_conf, dma_ch_samp_cos);
|
|
dma_channel_configure(dma_ch_samp_sin, &dma_conf, &PIO->sm[SM_SIN].instr, &samp_insn, 1,
|
|
false);
|
|
|
|
init_bias();
|
|
init_adder();
|
|
init_rx();
|
|
|
|
dma_channel_start(dma_ch_rx);
|
|
dma_channel_start(dma_ch_samp_cos);
|
|
|
|
pio_set_sm_mask_enabled(PIO, 0x0f, true);
|
|
}
|
|
|
|
static void rf_rx_stop(void)
|
|
{
|
|
pio_set_sm_mask_enabled(PIO, 0x0f, false);
|
|
|
|
pio_sm_restart(PIO, 0);
|
|
pio_sm_restart(PIO, 1);
|
|
pio_sm_restart(PIO, 2);
|
|
pio_sm_restart(PIO, 3);
|
|
|
|
pio_sm_clear_fifos(PIO, 0);
|
|
pio_sm_clear_fifos(PIO, 1);
|
|
pio_sm_clear_fifos(PIO, 2);
|
|
pio_sm_clear_fifos(PIO, 3);
|
|
|
|
sleep_us(10);
|
|
|
|
dma_channel_clear_chain_to(dma_ch_rx);
|
|
dma_channel_clear_chain_to(dma_ch_cp);
|
|
dma_channel_clear_chain_to(dma_ch_cos);
|
|
dma_channel_clear_chain_to(dma_ch_sin);
|
|
dma_channel_clear_chain_to(dma_ch_pio_cos);
|
|
dma_channel_clear_chain_to(dma_ch_pio_sin);
|
|
dma_channel_clear_chain_to(dma_ch_samp_cos);
|
|
dma_channel_clear_chain_to(dma_ch_samp_sin);
|
|
|
|
dma_channel_abort(dma_ch_rx);
|
|
dma_channel_abort(dma_ch_cp);
|
|
dma_channel_abort(dma_ch_cos);
|
|
dma_channel_abort(dma_ch_sin);
|
|
dma_channel_abort(dma_ch_pio_cos);
|
|
dma_channel_abort(dma_ch_pio_sin);
|
|
dma_channel_abort(dma_ch_samp_cos);
|
|
dma_channel_abort(dma_ch_samp_sin);
|
|
|
|
dma_channel_cleanup(dma_ch_rx);
|
|
dma_channel_cleanup(dma_ch_cp);
|
|
dma_channel_cleanup(dma_ch_cos);
|
|
dma_channel_cleanup(dma_ch_sin);
|
|
dma_channel_cleanup(dma_ch_pio_cos);
|
|
dma_channel_cleanup(dma_ch_pio_sin);
|
|
dma_channel_cleanup(dma_ch_samp_cos);
|
|
dma_channel_cleanup(dma_ch_samp_sin);
|
|
|
|
dma_channel_unclaim(dma_ch_rx);
|
|
dma_channel_unclaim(dma_ch_cp);
|
|
dma_channel_unclaim(dma_ch_cos);
|
|
dma_channel_unclaim(dma_ch_sin);
|
|
dma_channel_unclaim(dma_ch_pio_cos);
|
|
dma_channel_unclaim(dma_ch_pio_sin);
|
|
dma_channel_unclaim(dma_ch_samp_cos);
|
|
dma_channel_unclaim(dma_ch_samp_sin);
|
|
|
|
dma_ch_rx = -1;
|
|
dma_ch_cp = -1;
|
|
dma_ch_cos = -1;
|
|
dma_ch_sin = -1;
|
|
dma_ch_pio_cos = -1;
|
|
dma_ch_pio_sin = -1;
|
|
dma_ch_samp_cos = -1;
|
|
dma_ch_samp_sin = -1;
|
|
}
|
|
|
|
inline static void led_set(bool on)
|
|
{
|
|
gpio_put(PICO_DEFAULT_LED_PIN, on);
|
|
}
|
|
|
|
inline static uint32_t pio_sm_get_blocking_unsafe(pio_hw_t *pio, int sm)
|
|
{
|
|
while (pio->fstat & (1u << (PIO_FSTAT_RXEMPTY_LSB + sm)))
|
|
asm volatile("nop");
|
|
|
|
return pio->rxf[sm];
|
|
}
|
|
|
|
inline static int nextI()
|
|
{
|
|
static int prevI2, prevI1, prevI;
|
|
|
|
int sI2 = pio_sm_get_blocking_unsafe(PIO, SM_COS);
|
|
|
|
int I2 = sI2 - prevI2;
|
|
prevI2 = sI2;
|
|
|
|
int sI1 = pio_sm_get_blocking_unsafe(PIO, SM_COS);
|
|
int I1 = sI1 - prevI1;
|
|
prevI1 = sI1;
|
|
|
|
int sI = I2 + I2 + I1;
|
|
int I = sI - prevI;
|
|
prevI = sI;
|
|
|
|
return I;
|
|
}
|
|
|
|
inline static int nextQ()
|
|
{
|
|
static int prevQ2, prevQ1, prevQ;
|
|
|
|
int sQ2 = pio_sm_get_blocking_unsafe(PIO, SM_SIN);
|
|
|
|
int Q2 = sQ2 - prevQ2;
|
|
prevQ2 = sQ2;
|
|
|
|
int sQ1 = pio_sm_get_blocking_unsafe(PIO, SM_SIN);
|
|
int Q1 = sQ1 - prevQ1;
|
|
prevQ1 = sQ1;
|
|
|
|
int sQ = Q2 + Q2 + Q1;
|
|
int Q = sQ - prevQ;
|
|
prevQ = sQ;
|
|
|
|
return Q;
|
|
}
|
|
|
|
static void rf_rx(void)
|
|
{
|
|
while (true) {
|
|
if (multicore_fifo_rvalid()) {
|
|
multicore_fifo_pop_blocking();
|
|
multicore_fifo_push_blocking(0);
|
|
return;
|
|
}
|
|
|
|
uint8_t *block = iq_queue_buffer[iq_queue_pos];
|
|
uint8_t *blockptr = block;
|
|
|
|
for (int i = 0; i < IQ_SAMPLES; i++) {
|
|
int I = 0, Q = 0;
|
|
|
|
Q += nextQ();
|
|
I += nextI();
|
|
|
|
I -= nextQ();
|
|
Q += nextI();
|
|
|
|
Q -= nextQ();
|
|
I -= nextI();
|
|
|
|
I += nextQ();
|
|
Q -= nextI();
|
|
|
|
I *= gain;
|
|
I >>= ATTN_BITS;
|
|
|
|
*blockptr++ = I + 128;
|
|
|
|
Q *= gain;
|
|
Q >>= ATTN_BITS;
|
|
|
|
*blockptr++ = Q + 128;
|
|
}
|
|
|
|
if (queue_try_add(&iq_queue, &block)) {
|
|
iq_queue_pos = (iq_queue_pos + 1) % IQ_QUEUE_LEN;
|
|
led_set(0);
|
|
} else {
|
|
led_set(1);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void run_command(uint8_t cmd, uint32_t arg)
|
|
{
|
|
if (0x01 == cmd) {
|
|
/* Tune to a new center frequency */
|
|
frequency = arg;
|
|
rx_lo_init(frequency + sample_rate, true);
|
|
} else if (0x02 == cmd) {
|
|
/* Set the rate at which IQ sample pairs are sent */
|
|
sample_rate = arg;
|
|
gain = BASE_GAIN / (CLK_SYS_HZ / sample_rate / 2);
|
|
dma_timer_set_fraction(dma_t_samp, 1, CLK_SYS_HZ / (sample_rate * DECIMATE));
|
|
rx_lo_init(frequency + sample_rate, true);
|
|
}
|
|
}
|
|
|
|
static int check_command(void)
|
|
{
|
|
static uint8_t buf[5];
|
|
static int pos = 0;
|
|
|
|
int c;
|
|
|
|
while ((c = getchar_timeout_us(0)) >= 0) {
|
|
if (0 == pos && 0 == c)
|
|
return 0;
|
|
|
|
buf[pos++] = c;
|
|
|
|
if (5 == pos) {
|
|
uint32_t arg = (buf[1] << 24) | (buf[2] << 16) | (buf[3] << 8) | buf[4];
|
|
run_command(buf[0], arg);
|
|
pos = 0;
|
|
return buf[0];
|
|
}
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
static void do_rx()
|
|
{
|
|
const uint8_t *block;
|
|
|
|
while (queue_try_remove(&iq_queue, &block))
|
|
/* Flush the queue */;
|
|
|
|
rf_rx_start();
|
|
sleep_us(100);
|
|
|
|
multicore_launch_core1(rf_rx);
|
|
|
|
while (true) {
|
|
int cmd;
|
|
|
|
while ((cmd = check_command()) >= 0)
|
|
if (0 == cmd)
|
|
goto done;
|
|
|
|
if (queue_try_remove(&iq_queue, &block)) {
|
|
fwrite(block, IQ_BLOCK_LEN, 1, stdout);
|
|
fflush(stdout);
|
|
} else {
|
|
int wait = xorshift() >> (32 - 15);
|
|
|
|
for (int i = 0; i < wait; i++)
|
|
asm volatile("nop");
|
|
}
|
|
}
|
|
|
|
done:
|
|
multicore_fifo_push_blocking(0);
|
|
multicore_fifo_pop_blocking();
|
|
sleep_us(100);
|
|
multicore_reset_core1();
|
|
|
|
rf_rx_stop();
|
|
}
|
|
|
|
int main()
|
|
{
|
|
vreg_set_voltage(VREG_VOLTAGE);
|
|
set_sys_clock_khz(CLK_SYS_HZ / KHZ, true);
|
|
clock_configure(clk_peri, 0, CLOCKS_CLK_PERI_CTRL_AUXSRC_VALUE_CLKSRC_PLL_SYS, CLK_SYS_HZ,
|
|
CLK_SYS_HZ);
|
|
|
|
/* Enable PSU PWM mode. */
|
|
gpio_init(PSU_PIN);
|
|
gpio_set_dir(PSU_PIN, GPIO_OUT);
|
|
gpio_put(PSU_PIN, 1);
|
|
|
|
gpio_init(PICO_DEFAULT_LED_PIN);
|
|
gpio_set_dir(PICO_DEFAULT_LED_PIN, GPIO_OUT);
|
|
gpio_put(PICO_DEFAULT_LED_PIN, 0);
|
|
|
|
/* Prioritize DMA over CPU. */
|
|
bus_ctrl_hw->priority |= BUSCTRL_BUS_PRIORITY_DMA_W_BITS | BUSCTRL_BUS_PRIORITY_DMA_R_BITS;
|
|
|
|
stdio_usb_init();
|
|
setvbuf(stdout, NULL, _IONBF, 0);
|
|
|
|
queue_init(&iq_queue, sizeof(uint8_t *), IQ_QUEUE_LEN);
|
|
|
|
rx_lo_init(frequency + sample_rate, true);
|
|
|
|
/* We need to have the sampling timer ready. */
|
|
dma_t_samp = dma_claim_unused_timer(true);
|
|
dma_timer_set_fraction(dma_t_samp, 1, CLK_SYS_HZ / (sample_rate * DECIMATE));
|
|
|
|
while (true) {
|
|
if (check_command() > 0) {
|
|
static const uint32_t header[3] = { __builtin_bswap32(0x52544c30),
|
|
__builtin_bswap32(5),
|
|
__builtin_bswap32(29) };
|
|
fwrite(header, sizeof header, 1, stdout);
|
|
fflush(stdout);
|
|
|
|
do_rx();
|
|
}
|
|
|
|
sleep_ms(10);
|
|
}
|
|
}
|